.box {
    width: 1000px;
    height: 600px;
    margin: 10px auto;
    background-color: green;
    font-size: 50px;
    text-align: center;
    line-height: 600px;
  }
  .totop {
    display: none;
    position: fixed;
    bottom: 100px;
    right: 50px;
    width: 120px;
    height: 100px;
    background-color: skyblue;
    font-size: 26px;
    text-align: center;
    line-height: 100px;
  }
  .totop:hover {
    cursor: pointer;
    color: #fff;
  }

  .d-block{
      width: 1110px;
  }